<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <script src="/js/spritejs.js"></script>
  <script src="//lib.baomitu.com/dat-gui/0.7.2/dat.gui.min.js"></script>
  <style>
    #adaptive {
      width: 100%;
      padding-bottom: 50%;
      background: #eee;
    }
    #take-snapshot {
      margin-bottom: 6px;
    }
  </style>
</head>
<body>
  <div><button id="take-snapshot">存快照</button></div>
  <div id="adaptive"></div>
  <div id="snapshot-list"></div>
  <script>
    const {Scene, Sprite, Path} = spritejs;
    const container = document.getElementById('adaptive');
    const scene = new Scene({
      container,
      width: 1200,
      height: 600,
    });
    const bglayer = scene.layer('bglayer');
    const fglayer = scene.layer('fglayer');

    (async function () {
      function randomTriangle() {
        const triangle = new Path();
        const pos = [Math.random() * 1540, Math.random() * 600];
        const d = 'M0,0L0,10L8.66, 5z';
        triangle.attr({
          d,
          scale: 5,
          pos,
          fillColor: '#37c',
          rotate: Math.random() * 360,
        });
        bglayer.append(triangle);
      }

      for(let i = 0; i < 100; i++) {
        randomTriangle();
      }

      const birdsJsonUrl = 'https://s5.ssl.qhres.com/static/5f6911b7b91c88da.json';
      const birdsRes = 'https://p.ssl.qhimg.com/d/inn/c886d09f/birds.png';

      await scene.preload([birdsRes, birdsJsonUrl]);

      const bird = new Sprite('bird1.png');

      bird.attr({
        anchor: [0.5, 0.5],
        pos: [50, 200],
        scale: 0.6,
        offsetPath: 'M0,100C0,100,200,-100,500,100S700,-100,1000,100S1200,-100,1700,100S2200,-100,2700,100',
      });
      fglayer.append(bird);

      bird.animate([
        {texture: 'bird1.png'},
        {texture: 'bird2.png'},
        {texture: 'bird3.png'},
        {texture: 'bird1.png'},
      ], {
        duration: 300,
        iterations: Infinity,
        direction: 'alternate',
        easing: 'step-end',
      });

      bird.animate([
        {offsetDistance: 0},
        {offsetDistance: 1},
      ], {
        duration: 6000,
        iterations: Infinity,
      });

      const snapshotBtn = document.getElementById('take-snapshot'),
        snapshotList = document.getElementById('snapshot-list');

      snapshotBtn.addEventListener('click', async (evt) => {
        const canvas = await scene.snapshot();
        const snapshot = new Image();
        snapshot.src = canvas.toDataURL();
        const listItem = document.createElement('li');
        listItem.appendChild(snapshot);
        snapshotList.appendChild(listItem);
      });
    }());
  </script>
</body>
</html>
